Endovascular apparatus

ABSTRACT

Percutaneous treatment of aortic aneurysms and like vascular anomalies by an apparatus and method wherein the apparatus is delivered via catheter and comprises a sleeve with at least one peripheral conduit which is caused to assume an expanded, rigid configuration by the introduction of a chemical or mechanical hardening means, whereby the sleeve is caused to assume an open cylindrical configuration for fluid flow therethrough.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the percutaneous treatment of vesselsby an apparatus and method wherein the apparatus is delivered viacatheter and comprises a surgical graft which is fixated in a vessel bymeans of a chemical or mechanical hardening-filler material system.

2. General Background

Previous methods of treating aortic aneurysms include treatment viasurgical procedure in which an incision is made in the abdomen or chestof the patient, the diseased area is cleaned by the surgeon and anartificial graft is sutured in place. This highly invasive procedureusually results in long hospital stays and lengthy recoveries. Further,mortality and morbidity complications often result as a consequence ofthis surgical procedure.

Other percutaneous methods have been attempted, such as are disclosed inU.S. Pat. No. 4,577,631 (utilizing occlusion catheters with pressuresensitive adhesives), U.S. Pat. No. 4,740,207 (self-expanding stent-typematerials) and U.S. Pat. Nos. 4,271,839, 4,776,337 and 4,762,132 (otherstent derived devices).

There still exists a need, however, for a simple method of repairing avessel with an intravascular graft which allows normal tissue ingrowthto occur at the repair site. There exists a specific need for apercutaneous approach in which a catheter could be loaded with asurgical graft that can be fixated in a vessel such as the aorta.

SUMMARY OF THE INVENTION

The present invention provides devices for repairing aortic aneurysmsand the like. The intraluminal graft of the present invention in oneembodiment comprises a flexible linear or bifurcated tubular sleevedelivered to a repair site in a body by suitable means such as acatheter. The sleeve is suitably made of woven or cast material, and hasperipheral conduits or tubes at each end. Each conduit has at least asingle port that is connected to an elongated introduction meansassociated with the catheter delivery means. The introduction means maybe attached to the outer surface of the sleeve. The collapsed sleeve maybe made rigid and circular by the introduction through the introductionmeans of a chemical or mechanical hardening means.

The chemical hardening means may be a polymeric material introducedthrough the introduction means through an external source, such as acatheter or syringe. Alternatively, the mechanical hardening means maycomprise a single wire or multiple wires inserted into the conduits tosupport the ends, or any portion of the sleeve. The wires are notattached to the sleeve but reside in the conduits to provide a constantspring tension. The wires may be of any suitable material which retainsits tension, such as spring wire or memory wire.

The introduction means may be detached from the sleeve afterintroduction of the chemical or mechanical hardening means.

The sleeve may alternatively be associated with a fixation meanscomprising either a series of cylindrical tubules or an enclosure whichfits over the sleeve, with a hardening-filler system enclosed therein.The hardening-filler system includes an activatable hardening materialwhich may be provided in the form of microspheres that upon externalagitation may be disrupted, allowing the contents to react together andform a hardened material that fills the tubules or enclosure, therebyexpanding and rigidifying the fixation means, and fixing the sleeve inplace in the site of repair. Polymeric materials which are activatableinclude thioisocyanates, aldehydes, isocyanates, divinyl compounds,epoxides or acrylates. In addition to the aforementioned,photoactivatable crosslinkable groups as succinimidyl azido salicylate,succinimidyl-atidobenzoate, succinimidyl dithio acetate,azidoiodobenzene, fluoro nitrophenylazide, salicylate azides,benzophenone-maleimide, and the like may be used as photoactivatablecrosslinking reagents. The material may also consist of a thin coatingwhich can be activated by external forces such as laser, radiofrequency, ultrasound or the like, with the same hardening result takingplace. These materials would allow for normal tissue ingrowth to takeplace.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a perspective view of a vascular graft according to thepresent invention in a folded state prior to placement and expansionthereof;

FIG. 2 shows a perspective view of the vascular graft in an expandedstate by means of wires;

FIG. 3 is a perspective view of the device as in FIG. 2 showing theintroduction of chemical hardening material via syringe;

FIG. 4 is a perspective view of an alternate embodiment comprising aseries of cylindrical tubules;

FIG. 5 is a perspective view of an alternative embodiment of the device,where the vascular graft includes an enclosure which fits over thesleeve;

FIG. 6 is an alternative embodiment of the present invention having afluid track comprising a continuous cylindrical tubule which ishelically wound around the proximal and distal ends of the sleeve;

FIGS. 7 a and 7 b represent an alternative embodiment comprising abifurcated vascular graft including a dual guide wire delivery system;

FIGS. 8 a through 8 d show placement of a bifurcated vascular graftaccording to the present invention;

FIG. 9 shows a further alternative embodiment of a vascular graftaccording to the present invention;

FIGS. 10 a through 10 c show filling of the cylindrical tubules afterplacement of the graft;

FIGS. 11 a through 11 d are fragmentary views of vascular graftsaccording to the present invention; and

FIGS. 12 a and 12 b are cross sectional views of a vascular graftaccording to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a device and method for repairing ananeurysm or the like in a vessel, such as the aorta.

Referring to FIGS. 1 and 2, a vascular graft comprising a sleeve isshown generally at 10. Sleeve 10 is shown in a folded conformation inFIG. 1 and in an expanded state in FIG. 2. Sleeve 10 is either aflexible linear or bifurcated (as shown in FIGS. 7-12) tubular sleevemade of woven or extruded cast material. Sleeve 10 is made of abiocompatible polymeric material. Fabrics from which sleeve 10 may bemade are polyamides, such as nylon 6, nylon 6,6, and the like, Dacron®,polyesters, such as PET, polyethers, fluorinated polymers, such aspolytetrafluoroethylene (PTFE), or biodegradable or nonbiodegradablefibers derived from natural sources such as carbohydrates, collagens,and proteins. The fabric may be of a woven knit, or solid structure. Themost preferred materials are Dacron® and PTFE. Sleeve 10 is suitablydelivered by a catheter. Catheters of polyurethane, PTFE, PVC siliconeor the like with internal diameters of 1 to about 3 mm are suitable forpolymer injection.

Sleeve 10 has a proximal end 14, a distal end 16, an interior portion18, an exterior portion 20 and peripheral circular conduits or tubes22,24 located one at each end 14,16, respectively. Each conduit 22,24has at least one inlet port 26 and at least one outlet or exhaust port28, inlet(s) 26 being connected to elongated introduction means 30,32respectively. Introduction means 30,32 may be attached to exteriorportion 18 of sleeve 10. Referring to FIG. 2, collapsed sleeve 10 isexpanded and made rigid by the insertion of a spring wire or wires 34,36inserted through introduction means 30,32. A single wire or multiplewires may be inserted to support ends 14,16, the center body or anyportion of sleeve 10. Wires 34,36 are not attached to sleeve 10 butreside in introduction means 30,32 or conduits 22,24, providing aconstant spring tension. The entrance tubing may be detached from thesleeve after placement of supporting wires 34,36 in end tubes 22,24.

The supporting wire may be made of stainless steel, spring steel, memoryshape metals (such as nitinol, for example), titanium, or metal alloysof any kind, not limited to the aforementioned. Furthermore, theconfiguration of the supporting wire may be solid, braided or woven.

As shown in FIG. 3, the graft may be expanded and made rigid andcircular by a chemical hardening means introduced into a single spiraltube, or alternatively, as shown in FIG. 4, a series of interconnectedconcentric cylindrical tubules 40 attached to and encasing the sleeve10. Tubules 40 are interconnected by means of connecting tubes 41extending between the tubules. The chemical hardening means may beintroduced in the form of an injectable polymeric material comprised ofa one part system, a two part system, self expanding systems,thermosets, thermoplastics and the like. These polymers or polymericsystems would fill tubes 32 or tubules 40, causing them to expand andrigidify, thereby fixing the sleeve at the site of repair. Thisembodiment is of particular use for fusing such grafts in large vesselssuch as the aorta or pulmonary arteries.

Two part activatable hardening material may be supplied in the form ofmicrospheres (not shown) that upon agitation by an external force may bedisrupted. The external energy could originate from any suitable sourceincluding IR, visible or UV light through optic fiber on mechanicalvibrational means from about 1 to 100,000 hertz supplied by mechanicalor electrical transducers or by heat upon disruption of themicrospheres, the activatable hardening material is liberated andallowed to harden. Disruption of the microspheres releases the separatedcomponents, allowing the components to react together and form ahardened material that fills series of tubules 40 thereby fixing sleeve10 in place at the site of repair. Polymeric systems may be comprised ofvinyl or divinyl compounds in which an initiator is contained in themicrospheres, epoxies containing microencapsulated amine component, ordiisocyanates with encapsulated amine or hydroxyl terminatedprepolymers. Amino groups can be so isolated from methylacetimidate,ethyl acetimidate, dimethylglutarirnidate, dimethyl, adipidate, dimethylsebainidate, diisothionyl propionimidate, dimethyloxydipropionimidatesuccinate bis-esters, disuccinimidyl tartarate,dicyanatobenzene, dichlorodinitrobenzene, adipaldehyde, glutaraldehydeand the like.

These hardening-filler systems would allow for normal tissue ingrowth inseries of tubules 40 to take place. Because the tubules comprise only asmall fraction of the total surface area of the sleeve, these hardeningfilling systems would allow for tissue ingrowth to take place into thesleeve material not impeded by the tubules, providing furtherreinforcement of the placement of the sleeve 10.

In a further embodiment shown in FIG. 5, the material may be introducedby means of a hardening-filler system comprising an enclosure 50attached to sleeve 10. Enclosure 50, like tubules 40, is filled with anactivatable hardening material consisting of either a one-part polymersystem, a two-part polymer system or a self-expanding monomer, whichupon polymerization would fill enclosure 50, causing it to expand andrigidify, thereby fixing sleeve 10 at the site of repair. Theactivatable hardening material is described above with reference to FIG.4.

Referring now to FIG. 6, an alternative embodiment of sleeve 10 is shownin place at a repair site 60. Sleeve 10 has a fluid track comprising acontinuous cylindrical tubule 40 which is helically wound aroundproximal end 14 and distal end 16 of sleeve 10. Tubule 40 can be filledwith a curing polymer selected from thermoset polymers or two partpolymers, as described hereinabove. Sleeve 10 may optionally includesupplemental physical attachment means (not shown) such as spikes, barbsor the like at proximal and distal ends 14,16.

FIGS. 7-9 represent an alternative embodiment comprising a bifurcatedvascular graft 110 including a dual guide wire delivery system 112.Graft 110 has a proximal end 114 and at least two distal-ends 116,118.FIGS. 8 a through 8 d show placement of bifurcated vascular graft 110 ata repair site 160 where the vessel bifurcates. Graft 110 and deliverysystem 112 are advanced through a vessel to repair site 160. Deliverysystem 112 includes guide wires 120,122 whereby ends 114,116,118 areplaced at different branches of the vessel bifurcation. FIG. 7 b showsgraft 110 in place at site 160.

FIGS. 9-12 show an alternative embodiment of a vascular graft accordingto the present invention, indicated generally at 210. Graft 210 hasproximal and distal ends 214,216 and cylindrical tubule 240. Tubule 240has a first end 242 and a second end 244, located near proximal end 214.After placement of graft 210, tubule 240 is filled.

Referring to FIGS. 10 a, 10 b and 10 c, filling means 250 is shown.Although filling means 250 is shown in conjunction with a tubularvascular graft, such a filling means may be used with any vascular graftaccording to the present invention. Filling means 250 comprises casing251, filling tube 252 with distal infusion inlet 254 and exhaust tube256 with distal exhaust vent 258. Filling means 250 may be incorporatedinto the vascular graft delivery means or may alternatively be separatefrom, but associated with the delivery means. FIG. 10 b is an enlargedfragmentary view of filling tube 252 which shows the manner in whichinfusion inlet 254 connects to first end 242 of tubule 240, via pinchring 262 located near the distal end of infusion inlet 254. Distal endof infusion inlet 254 is advanced into end 242 of tubule 240 until pinchring 262 is inserted in tubule 240. As shown in FIG. 10 c, casing 251 offilling means 250 is advanced over end 242 of tubule 240 whereby pinchring 262 creates an interference fit between filling tube 252 and end242 of tubule 240. Exhaust vent 258 connects to end 244 of tubule 240 inthe same manner.

FIGS. 11-12 show alternative embodiments of the inventive vasculargraft. FIG. 11 a shows a graft 310 having an outer layer 370 surroundingtubules 340. FIG. 11 b shows graft 310 having two outer layers 370,372surrounding tubules 340. FIG. 11 c shows graft 410 having no outer layerover tubules 440, and lacking connection between tubule 440 and proximalcoil 480. FIG. 11 d shows a cross section of graft 510, having an innercore 590. FIGS. 12 a and 12 b show a longitudinal cross section of graft610 in place in repair site 660, wherein graft 610 has an enlargedproximal coil 680 located directly at proximal end 614 of graft 610,i.e. not more than about 5 mm from proximal end 614.

The unique features of the device are the manner of its delivery andfixation at the site of repair, its low profile which may preventinterference with normal heart functions, and the non-invasive nature ofthe delivery which would reduce costs normally associated with closureof such a defect. The device and method of fixation provides anon-invasive treatment of aortic aneurysms and the like. The device ismade of polymeric material and is delivered via catheter in anon-invasive procedure. In one embodiment, the device operates throughchemical means to repair an aneurysm.

Advantages of the apparatus and method of the present invention aremany. No preformed stent is required and the apparatus has a smallerinsertion diameter than previous vascular grafts. Further, the vasculargraft has a lower cost of production than previous graft materials andprocedures.

The practice of the present invention achieves several objectives andadvantages. Currently, there are no percutaneous devices available tocure a septal defect or the like. The device and method of the presentinvention provides an advantage over surgery in that the cost of theprocedure is substantially less, the risk of infection is less, thehospital residency time is less and there is no physically deformingscar.

Further advantages include applicability to procedures such as repair ofPDA, patent ductus anomaly. The non-invasive mode of delivery wouldreduce costs associated with this type of procedure. In addition, thelow profile of the apparatus may minimize or prevent interference withnormal heart functions.

While this invention may be embodied in many different forms, there aredescribed in detail herein specific preferred embodiments of theinvention. This description is an exemplification of the principles ofthe invention and is not intended to limit the invention to theparticular embodiments illustrated.

The above Examples and disclosure are intended to be illustrative andnot exhaustive. These examples and description will suggest manyvariations and alternatives to one of ordinary skill in this art. Allthese alternatives and variations are intended to be included within thescope of the attached claims. Those familiar with the art may recognizeother equivalents to the specific embodiments described herein whichequivalents are also intended to be encompassed by the claims attachedhereto.

1-29. (canceled)
 30. An expandable stent for insertion into a passage,said expandable stent comprising a body formed of at least one flexiblematerial, said body being convertible from a collapsed condition inwhich it is of a size to be inserted into the passage into an expandedcondition in which the body is fixed relative to the passage, passagemeans in said body comprising a plurality of spaced apart channelsdisposed transversely about the body and extending over at least aregion of the body, said plurality of channels in communication with oneanother, said inlet means communicating with said passage means toenable a rigidifying material to be introduced into said passage meansso that, in use, at least said region of said body can be rigidifiedwith a rigidifying material whereby to maintain the body in its expandedcondition, the rigidifying material being introduced into said passagemeans through said inlet means.
 31. The stent of claim 30, wherein thebody is formed of at least one flexible sheet material.
 32. The stent ofclaim 30, wherein said at least one flexible sheet material is tubularor includes a tubular region.
 33. The stent of claim 30, wherein theinlet means is closable.
 34. The stent of claim 30, further comprising afiller means communicating with said passage means in the body via theinlet means.
 35. The stent of claim 30, wherein the body comprises asidewall which fixedly engages with a sidewall of the passage in use, isformed of at least one flexible sheet material.
 36. The stent of claim30, wherein the passage means is disposed inwardly or outwardly of saidat least one flexible sheet material or between multiple flexible sheetswhen more than one is provided.
 37. An expandable stent for insertioninto a passage, said expandable device comprising: a. a body formed ofat least one flexible material, said body being convertible from acollapsed condition in which it is of a size to be inserted into thepassage into an expanded condition in which the body is fixed relativeto the passage, b. passage means in said body, said passage meansincluding a main channel in communication with a plurality of channelsextending transversely from the main channel, extending over at least aregion of the body, and being spaced by portions of the body, c. inletmeans communicating with said passage means, and d. flowable rigidifyingmaterial introducible into the passage means, the material rigidifyingwithin the passage means to thereby maintain the body in the expandedcondition.
 38. A stent as claimed in claim 37, wherein the body isformed of at least one flexible sheet material.
 39. A stent as claimedin claim 37, wherein the inlet means is closable.
 40. A stent as claimedin claim 37, wherein the sidewall of the body which fixedly engages withthe sidewall of the passage in use, is formed of at least one flexiblesheet material.
 41. A stent as claimed in claim 37, wherein the passagemeans is disposed inwardly or outwardly of said at least one flexiblesheet material or between the flexible sheet materials when more thanone is provided.
 42. The expandable stent of claim 37, wherein theflowable rigidifying material comprises at least one component selectedfrom the following group: a. a polymerizable monomer; and b. apre-polymer.
 43. The expandable stent of claim 37, wherein the flowablerigidifying material includes at least one of: a. epoxides; and b.acrylates.
 44. The expandable stent of claim 37, wherein the flowablerigidifying material comprises at least two components wherein thecomponents rigidify after their combination occurs.
 45. A stent forinsertion in a body passage comprising: a thin fabric formed with aplurality of flexible channels discretely spaced from each other andhaving a first condition in which said thin fabric is collapsed and asecond condition in which said thin fabric is expanded to conform to ashape of at least a part of said passage when said thin fabric isdisposed within said passage, said channels including a main channel incommunication with subsidiary channels transversely extending from saidmain channel and said channel having a flowable rigidifying materialtherein, wherein rigidification of the material fixes the channelssurrounding the material against flexion.
 46. The stent of claim 45,wherein said thin fabric includes two superimposed sheets, said sheetshaving sealed regions and unsealed regions, said sheets being joinedalong said sealed regions and forming said channels in said unsealedregions.
 47. The stent of claim 45, wherein said channels form ridgesalong said unsealed regions when filled with said rigidifying matter,said ridges being adapted to engage said passage to maintain said devicewithin said passage.
 48. The stent claim 45, wherein said channelsinclude an inlet adapted to receive said rigidifying matter, and mainchannel in communication with said inlet.
 49. The stent of claim 45,wherein said thin fabric is arranged and constructed in said secondcondition to maintain said passage open.
 50. An expandable stent forinsertion into a lumen, the stent: a. being formed of flexible material;b. being convertible; (1) from a collapsed condition wherein the stentis insertable into the lumen; (2) into an expanded condition wherein thestent extends over and supports the surface of the lumen, and whereinthe stent at least partially encircles an interior passage extendingalong the lumen; and c. having areas thereon spaced by expandablechannels, said channels including a main channel in communication withsubsidiary channels extending transversely from said main channel,wherein the expandable channels have fluid rigidifying material thereinwhich maintains the stent in the expanded condition, the materialrigidifying to fix the device in the expanded condition.
 51. Theexpandable stent of claim 50, wherein the expandable channels havewidths shorter than the spacing between the expandable channels.
 52. Theexpandable stent of claim 50, wherein the expandable channels, whenexpanded, define a framework of at least substantially tubular shape.53. The expandable stent of claim 50, wherein the expandable channelsextend about the interior passage in an at least substantiallycircumferential direction.
 54. The expandable stent of claim 50, whereinthe stent is tubular with the interior passage extending therein betweenopposing ends of the stent, the interior passage being collapsed whenthe stent is in its collapsed condition.
 55. The expandable stent ofclaim 50, wherein the device is sheetlike with opposing sides when inits collapsed condition, with the stent curving to adjacently situateits opposing sides to define the interior passage when in its expandedcondition.
 56. An expandable stent for insertion into a lumen, thedevice: a. including one or more flexible channels expandable: (1) froma collapsed state, to (2) an expanded state wherein the channels definea framework which at least partially surrounds an interior passageextending along the lumen; and b. webs of flexible material spacing thechannels, wherein the device may be drawn through the lumen when thechannels are in the collapsed state; and the channels may subsequentlybe put in their expanded state to have the framework and webs extendabout and support the surface of the lumen, and wherein the channels arefilled with fluid rigidify material, the material flowing to inflate thechannels to their expanded state and subsequently rigidifying into anonflowing state to fix the channels against collapse.
 57. Theexpandable stent of claim 56, wherein the channels have widths shorterthan the spacing between the channels.
 58. The expandable stent of claim56, wherein the framework has at least substantially tubular shape. 59.The expandable stent of claim 56, wherein the channels extend in an atleast substantially circumferential direction about the interior passageof the framework.
 60. The expandable stent of claim 56, wherein thestent is sheetlike with opposing sides when in its collapsed state, withthe stent curving about the interior passage with its opposing sidesadjacently situated when in its expanded condition.
 61. An expandablestent for insertion into a lumen, the device: a. including expandablechannels having widths spaced by one or more areas of flexible material,and wherein the spacing between the expandable channels is at least asgreat as their widths, and b. being convertible between: (1) a collapsedstate wherein the expandable channels are at least substantially emptyand the stent is movable within the lumen, and (2) an expandable statewherein the expandable channels are filled with flowable rigidifyingmaterial to extend along and support the surface of the lumen, with theexpandable channels at least partially encircling and maintaining apassage within the lumen, and wherein the rigidifying materialrigidifies to a non-flowing state to fix the channels in place.
 62. Theexpandable stent of claim 61, wherein the expandable channels, whenexpanded, define a framework of at least substantially tubular shape.63. The expandable stent of claim 61, wherein the expandable channelsextend in an at least substantially circumferential direction about thepassage.
 64. The expandable stent of claim 61, wherein the device istubular with the passage extending therein between opposing ends of thestent, the passage being collapsed when the stent is in its collapsedstate.
 65. The expandable stent of claim 61, wherein the stent is sheetlike with opposing sides when in its collapsed state, with the stentcurving about the interior passage with adjacently situated sides whenin its expanded state.